The invention relates to a process for cutting films in laminated glass with a blade and a device which is suitable for executing the process and which is equipped with a blade.
Devices for cutting through the film of laminated glass as are known for example from EP 0 708 741 B are a component of devices for dividing laminated glass and are used to cut through the plastic film which is located between the panes of laminated glass after breaking the two panes and pulling them apart in order to complete separation of the laminated glass.
EP 0 708 741 B discloses a cutting device with a blade for cutting through the film in laminated glass.
The blade in the known device sits in a blade holding device which can be moved along the dividing line and can be swivelled around an axis which is aligned parallel to the movement device. In the known cutting device the blade is made with a straight cutting edge and is attached in a clamp block. So that the blade is also reliably guided in the gap between the parts of the laminated glass, when the film is cut, in front of the blade there is a guide disk which dips into the gap between the disks.
The problem in the known device is that difficulties can arise when the blade is not immersed deeply enough into the gaps between the panes in order to reliably cut through the film and that the blade can run onto the edges of the glass panes bordering the gap regardless of the guide disk and can be damaged in doing so. This occurs especially in a rough cut or for glass parts projecting into the gap.
The object of the invention is to devise a process and a device of the initially mentioned type which does not have these defects.
According to the process as claimed in the invention it is possible to proceed as follows.
The blade is seated on the surface of one (the top or the bottom) pane of laminated glass next to the opened gap by movement of the part of the device which holds the blade in the direction to the laminated glass. At this point the blade is pushed by lateral displacement, especially swivelling of the holding part around the axis aligned parallel to the cutting direction laterally, i.e. transversely to the gap, until the blade dips into the gap. At this point the blade is pushed further (lowered or lifted) until a measurement device, for example, a rule, establishes that the blade has been moved deeply enough into the gap to reliably cut the film. As soon as this has taken place, either the blade is held down, when it acts on the film from the top by its own weight and the weight of the holding part, this is optionally supported by (another) hydraulic cylinder, or, when the blade acts from underneath on the film, it is loaded upwardly in order to keep it engaged effectively for cutting through the film, and the cutting process can begin.
The procedure as claimed in the invention makes it possible for the blade to dip reliably into the gap between the two parts of the laminated glass when the laminated glass has moved for example when breaking the two glass panes in the direction of its surface extension, for example transversely to the gap relative to the original location in which the glass panes of the laminated glass have been scratched. Thus the blade always reliably finds the gap.
Advantageously, within the framework of the invention it is provided that for lateral adjustment of the blade in the xe2x80x9csearchxe2x80x9d for the gap between the glass panes there is a hydraulic cylinder which engages the swivelling carrier.
The blade dips into the gap preferably such that a holding device similar to a parallelogram rod for the blade is actuated. The cylinder for adjusting the blade touching the top glass pane (and for raising the blade) is coupled to the blade holding device for example such that the blade is not pressed with force against the glass surface. This can be done by a peg-slot guide being provided between the blade holding device and the hydraulic cylinder or the component which the hydraulic cylinder engages.
The blade with which the process as claimed in the invention is carried out can be made as desired. Thus for example blades with a straight cutting edge can be used.
Preferably, within the framework of the invention a circular blade is used which makes it possible to move the sharp points of the blade into the working position by turning again and again. The blade is held on the holding part preferably using a clamping device which is equipped for example with a manually actuated thumb screw.
The device as claimed in the invention for cutting through the film of laminated glass can be used on optionally configured laminated glass cutting tables. Examples of these laminated glass cutting tables are described in EP 0 708 741 B, AT 403 688 B and in DE 195 19 093 A. In part the cutting device proposed as claimed in the invention with a blade can replace the other devices provided in the older proposals for cutting through the film between the panes of laminated glass.